package main

import "fmt"

func main() {
   var countryCapitalMap map[string]string
   /* 创建集合 */
   countryCapitalMap = make(map[string]string)
   
   /* map 插入 key-value 对，各个国家对应的首都 */
   countryCapitalMap["France"] = "Paris"
   countryCapitalMap["Italy"] = "Rome"
   countryCapitalMap["Japan"] = "Tokyo"
   countryCapitalMap["India"] = "New Delhi"
   
   /* 使用 key 输出 map 值 */
   for country := range countryCapitalMap {
      fmt.Println("Capital of",country,"is",countryCapitalMap[country])
   }   
   
   /* 查看元素在集合中是否存在 */
   captial, ok := countryCapitalMap["United States"]
   /* 如果 ok 是 true, 则存在，否则不存在 */
   if(ok){
      fmt.Println("Capital of United States is", captial)  
   } else {
      fmt.Println("Capital of United States is not present") 
   }   

   /* 删除元素 */
   delete(countryCapitalMap,"France")
   fmt.Println("Entry for France is deleted")  
   
   fmt.Println("删除元素后 map")   
   
   /* 打印 map */
   for country := range countryCapitalMap {
      fmt.Println("Capital of",country,"is",countryCapitalMap[country])
   }   
}